U.S. Pat. No. 5,865,241, which issued Feb. 2, 1999 to Exco Technologies Limited, discloses a three-part die casting machine for casting engine blocks with an ejector holder block that closes on a stationary die half, and an ejector box that moves to backstop the ejector holder block. Die core pieces in the ejector holder block (used to form piston cylinder bores) slide at an acute angle to the direction of movement of the holder block. With the die core pieces extended, hydraulic cylinders between the ejector box and ejector holder block retract the ejector holder block rearwardly into abutment with the ejector box. Thereafter, a hydraulic cylinder pushes the ejector box and the mated ejector holder block against the stationary die half to form a die cavity between the stationary die half and the ejector holder block which is further defined by the extended die core pieces. In this closed position, the ejector box backstops the die core pieces to lock the die core pieces in their extended position. After casting, the die cavity is opened along the main parting line between the ejector holder block and the stationary die half. Once the ejector holder block has been retracted from the stationary die half to a sufficient extent, the hydraulic cylinders connecting the ejector box and the ejector holder block push the ejector holder block forward away from the ejector box to allow withdrawal of the die core pieces.
The die core pieces of the described die casting machine have a typical service life of about 8,000 cycles. It would be desirable to increase the service life of the die core pieces. It would also be desirable to reduce the cycle time of the die casting machine.